The objective of this project is to develop, test and manufacture a safety device, of the size of a pager, that will be packaged into a belt, called "SafetyBelt". This device will protect construction workers from two of the major worksite accidents: (i) struck against moving equipment, and caught in/under/between, and (ii) falls through floor, wall and roof openings, and falls from open-sided floors. These accidents account for 19.8% of the construction accidents and cost the nation $524 million, annually. The SafetyBelt will utilize ultrasonic or electromagnetic sensors, a battery, a circuit board, and an alarm to alert the worker of an approaching hazard (a vehicle, heavy equipment, or an unguarded floor opening etc.). A red flashing light coming out of the safety device will warn the approaching heavy machinery from hitting the worker, and alert co-workers in the vicinity of the opening and/or the approaching equipment. Two hundred (200) of the SafetyBelt prototypes will be field-tested at selected construction sites of different types for accuracy and reliability. A control group of 200 workers at similar worksites will be monitored for evaluating the effectiveness of the SafetyBelt. A 50% usage of the SafetyBelt will save 78 lives, 27 permanent-total disabilities and 12,750 permanent-partial disabilities per year. PROPOSED COMMERCIAL APPLICATION: The SafetyBelt will be worn by construction workers on heavy highway construction projects, on the construction of water supply, sewage and drainage utilities, and on the construction of general buildings and residential buildings. It is estimated that about 3.0 million construction workers --50% of the total construction work force-- will use the SafetyBelt, resulting in safety savings of $262 million every year.